Check out this mini handheld keyboard with a built-in touchpad. 'Aint she a weird one?
mini handheld keyboard
The USB 2.4GHz Multimedia Keyboard consists of 85 keys, a touchpad and laser pointer.
Pick one up for $36 (£22) over at Brando. ®
mini handheld keyboard

Windows only?

In my experience, most wireless keyboard/pointer combos work fine with Linux - I think that at least on some PCs, the PC hardware itself interacts with the USB receiver at a sub-OS level (possibly at the BIOS level or close to it). I've used such a device with a Foxconn NT330i "nettop" running Ubuntu, and was able to use the keyboard even in the BIOS setup screen (i.e. before the OS loads in).